The seat adjuster arrangement of this invention is similar to those shown in Ser. No. 383,471, Vertical Seat Adjuster for Vehicle Seats, Richard W. A. Rees, filed June 1, 1982, and Ser. No. 407,320, Vertical Seat Adjuster Arrangement for Vehicle Seats, Otto J. Langmesser Jr. and Richard W. A. Rees, filed Aug. 12, 1982, both assigned to the assignee of this invention. Both seat adjuster arrangements include inboard and outboard seat adjuster mechanisms of different hand. Each mechanism obtains vertical adjustment of the front or rear portion of the seat through rotation of respective spaced front and rear levers which are pivoted both to a seat support bracket supporting the seat and to a relatively fixed respective vehicle pivotal connection. Conjoint rotation of the front and rear pairs of levers of the inboard and outboard mechanisms about their relatively fixed vehicle pivotal connections is assured by transfer tubes interconnecting the seat support bracket pivots of the levers. Such rotation raises and lowers the respective front and rear portions of the seat and occurs by the seat occupant shifting weight.
In the Rees structure, the seat support bracket of the outboard seat adjuster mechanism slidably mounts a pair of lock plates, each respective to one of the vehicle pivotal connections and having a notched edge engageable with such pivotal connection to lock the corresponding portion of the seat in one of a plurality of vertical positions, the number of positions being equal to the number of notches. The lock plates are selectively and alternately movable to a released position to move the notch thereof out of engagement with a respective vehicle pivotal connection and permit movement of the corresponding portion of the seat and seat support bracket to a new vertical position wherein the notch of the lock plate corresponding to that position is reengaged to lock the seat in the new vertical position.
In the Langmesser and Rees structure, a manually operable screwjack mechanism is coupled to the transfer tube interconnecting the rear levers to rotate such levers and vertically adjust the rear portion of the seat. The screwjack mechanism holds the rear portion of the seat in a vertically adjusted position.
The seat support brackets of the inboard and outboard seat adjuster mechanisms are each provided with a lock plate which is slidably mounted thereon for movement between engaged and released positions relative to a respective front vehicle pivotal connection. Each lock plate includes a series of alternating notches and teeth. The notches and teeth of one lock plate are offset with respect to those of the other lock plate so that each notch of one lock plate corresponds to a tooth of the other lock plate. Thus, when a notch of one lock plate engages a respective pivotal connection, a tooth of the other lock plate abuts a respective pivotal connection whereby one lock plate is always engaged and the other lock plate is always released in each vertically adjusted position of the seat. The seat is locked in each vertically adjusted position since the front levers are coupled together for conjoint rotation by the front transfer tube. The alternating teeth and abutments which are offset with respect to each other provides a greater number of vertically adjusted positions than can be obtained if the notches and teeth are aligned with respect to each other.
In the structure of this invention, both lock plates are mounted to the same seat support bracket, one inboard of the bracket and the other outboard of the bracket. In the preferred embodiment, the outboard lock plate is planar and the edges thereof mount shoes which slidably mount the lock plate between flanges of the seat support bracket. The plate slidably bears against the planar web of the seat support bracket and is connected thereto. Thus the lock plate is effectively trapped against any tilting movement relative to the seat support bracket. The inboard lock plate is also planar and also mounts shoes on the edges thereof. These shoes are received between the flanges of a bracket mounted to the seat support bracket and of the same cross-section thereof. Additionally the shoes of the inboard lock plate are trapped between an auxiliary bracket and the seat support bracket such that the inboard lock plate is also effectively trapped against tilting movement relative to the planar web of the inboard bracket against which it slidably bears. Since the shoes are trapped between the auxiliary bracket and the seat support bracket, no slidable connection is necessary between the lock plate and the auxiliary bracket. This arrangement of the lock plate simplifies the manual release mechanism for selectively moving the lock plates to released position to permit vertical adjustment of the front portion of the seat and the holding of the front portion in the new position by engagement of a notch of one lock plate with a front pivotal connection between the seat support bracket and the vehicle.
The rear portion of the seat is vertically adjusted and held in various vertically adjusted positions by a screwjack mechanism similar to that of the Langmesser and Rees structure. However, the screwjack mechanism of this invention includes a spring clip which has U-shaped leg portions thereof mounted within openings in an internally threaded tube of the screwjack and normally bearing against the threaded outer surface of the screw. In order to fix the upper vertical position of the rear of the seat, the screw is provided with a pair of circumferentially facing shoulders, generally diametrically opposite to each other, and a leadin surface to each shoulder which generally follows a helical path defined by a plurality of threads of the screw. When the screw has moved axially relative to the tube to a position wherein the rear portion of the seat is at the maximum permissible vertical height, the U-shaped legs of the spring clip on the tube engage and ride along the spiral cams until they engage the circumferential shoulders to thereby limit any relative further movement of the screw and the tube and fix the seat in the maximum vertically elevated position.
One feature of this invention is that it provides an improved seat adjuster arrangement for vehicle seats which includes a seat support bracket having a portion thereof mounted to the vehicle by a lever, with a pair of lock plates being mounted on opposite sides of a planar portion of the bracket for sliding movement relative thereto between engaged and disengaged positions relative to the pivotal connection of the lever to the vehicle, with the lock plates being selectively movable between engaged and released positions relative to the pivotal connection to selectively permit vertical adjustment of the portion of the bracket or hold such portion against adjustment. Another feature is that the lock plates have alternating teeth and notches offset with respect to each other laterally of the planar portion of the seat support bracket, with the notch of one lock plate engaging the pivot while a tooth of the other lock plate simultaneously engages the pivot, with both lock plates being simultaneously movable out of engagement with the pivot to permit adjustment of the portion of the seat support bracket. Yet another feature is that a single release member is pivotally and slidably connected to both lock plates to move both lock plates simultaneously to released position but permit both a notch of one lock plate and a tooth of the other lock plate to simultaneously engage the pivotal connection of the lever to the vehicle. Yet another feature is that another portion of the seat is vertically adjusted by a screwjack mechanism which includes radially extending means on one of the members of the screwjack which is resiliently engageable with radially facing shoulders of the other member of the screwjack to provide a limiting stop limiting movement of the members relative to each other and setting a maximum adjustment position of the seat support bracket relative to the vehicle.